The absence of endogenous lipase from oil palm mesocarp

Oil palm (Elaeis guineensis Jacq.) fruit mesocarp had higher levels of free fatty acids at the ends of the fruits than in the middle, and microscopy showed that yeasts penetrate the mesocarp via the scars at each end. Very low levels of esterase activity, probably not due to a lipase, were detected in mesocarp extracts by using 4-methyl umbelliferone esters as substrates, but no activity against triacylglycerols could be found. In bruising and storage trials, the only variable that correlated (P<0.01) with free fatty acid level was yeast and mould count. It is concluded that yeasts and moulds are the source of lipolytic activity in oil palm mesocarp, and there is no evidence for an endogenous lipase.     

亚临界水提取油棕果渣多酚响应面优化研究

目的为了更好地利用农副产品,回收利用农业废弃物中的有效成分,以油棕果脱壳提油后的废弃物——油棕果渣为原料,以亚临界水技术萃取果渣中酚类物质。方法通过单因素实验对料液比、时间、温度等工艺参数进行研究,并用响应面Box-Behnken试验设计对提取工艺进行优化,建立二次多项数学模型。结果最终通过验证得到亚临界水萃取油棕果渣多酚类物质的最优的工艺条件:液料比50 m L/g,时间40 min,温度250℃。实际测得多酚含量为6.26 g/100 g,与理论值相符合。结论本研究对生产实际具有良好的参考指导作用。     

Preservation of oil palm fruit and oil palm fruit mesocarp by gamma irradiation

Experiments were conducted to determine the potential of gamma radiations in the extension of the shelf-life of oil palm fruit and oil palm fruit mesocarp. In the course of the experiment, it was observed that even though palm fruits in their harvested form, went bad within 3 days post-harvest, their shelf-life can be extended to at least 2 months through preparation of dry oil palm fruit mesocarp. Furthermore, despite the fact that gamma radiation cannot be used to prolong the shelf-life of oil palm fruit proper, it can be used to drastically reduce the mould load in the dry palm fruit mesocarps, thereby further enhancing their keeping quality and consumer acceptance. Chemical and organoleptic analyses of fat extracted from irradiated, dry oil palm fruit mesocarp show that there is practically no radiation effect. The significance of these observations is discussed in relation to the possible acceptance of radiation-preservation of oil palm fruit mesocarp commercially.     

Supercritical fluid extraction of β-carotene from crude palm oil using CO2

The aim of this study was to ascertain the influence of pressure, temperature and time on the supercritical fluid extraction of β-carotene from the crude palm oil. The operating conditions were shown as follows: pressures of 75, 125 and 175 bar, temperatures of 80, 100 and 120 °C and extraction time of 1, 3 and 5 h. The extracts were analyzed using UV spectroscopy at a wavelength of 450 nm. Then the experimental data was compared with the data obtained using a statistical method. The results from the model showed a good agreement with the experimental data. The results (obtained from the statistical model) demonstrate that a pressure of 140 bar, temperature of 102 °C and extraction time of 3.14 h are required to obtain optimum yield of β-carotene (1.028 × 10⁻²%) from the extraction process, however the maximum yield of the β-carotene (1.741 × 10⁻²%) was experimentally obtained at a pressure of 75 bar, temperature of 120 °C and extraction time of 1 h.     

Analysis of mesocarp and kernel oils from the American oil palm and F1 hybrids with the West African oil palm

The mesocarp oil of the American oil palm is more unsaturated than that of the West African oil palm. Mesocarp oils obtained from F₁ hybrids of these two oil palms exhibit an intermediate degree of unsaturation. Hybrid kernel oils are similar in composition to that of their West African oil palm parent, whereas kernel oils from the American oil palm are considerably more unsaturated and exhibit a unique fatty acid composition among seed fats of the Palmae family.     

Extraction of β-carotenes from palm oil mesocarp using sub-critical R134a

Sub-critical extraction of palm oil from palm mesocarp using R134a solvent was conducted via the dynamic mode to investigate the ability of R134a to extract β-carotene. The yield of palm oil and the solubility of β-carotene were investigated at 40, 60 and 80 °C and pressure range from 45–100 bar. The extracted oil was analysed for β-carotene content using UV–Vis spectrophotometry. The results showed that palm oil yield increased with pressure and temperature. The maximum solubility of β-carotene was obtained at 100 bar and 60 °C while the lowest solubility occurred at 80 bar and 40 °C. The higher concentration of extracted β-carotene ranging from 330–780 ppm as compared to that achieved through conventional palm oil processing indicates that extraction of β-carotene using R134a is viable.     

Central composite design for the optimization of supercritical carbon dioxide fluid extraction of fatty acids from Borago officinalis L. flower

Abstract: In the present study, fatty acids and essential oils of the flower of borage (Borago officinalis L.) were obtained by supercritical carbon dioxide fluid extraction under different conditions. The extracts obtained were compared to oils of borage flower oil isolated by hydrodistillation. The obtained oils were analyzed by gas chromatography mass spectrometry. The compounds were identified according to their retention indices and mass spectra. The experimental parameters of supercritical fluid extraction (SFE) were optimized using a central composite design after a full factorial experimental design. Extraction yields based on SFE varied in the range of 0.02% to 1.96% (w/w), and the oil yield based on the hydrodistillation was 0.05% (v/w). The optimum conditions of SFE were obtained at a pressure of 350 atm, a temperature of 65 °C, a methanol modifier volume of 100 μL, and static and dynamic extraction time of 10 min. Main components of the extracts under optimum SFE conditions were palmitic acid, linoleic acid, γ‐linolenic acid, and oleic acid. The results indicated that by using the suitable extraction conditions, SFE is more effective than the conventional hydrodistillation method in the extraction of fatty acids and the preservation of its quality. Practical Application: SFE is a good technique for the extraction of oils from plants. The extraction yields by SFE are more than the conventional method. SFE is used on a large scale for production of essential oils and pharmaceutical products from plants.     

Supercritical fluid extraction of β-carotene from crude palm oil using CO2

The aim of this study was to ascertain the influence of pressure, temperature and time on the supercritical fluid extraction of β-carotene from the crude palm oil. The operating conditions were shown as follows: pressures of 75, 125 and 175 bar, temperatures of 80, 100 and 120 °C and extraction time of 1, 3 and 5 h. The extracts were analyzed using UV spectroscopy at a wavelength of 450 nm. Then the experimental data was compared with the data obtained using a statistical method. The results from the model showed a good agreement with the experimental data. The results (obtained from the statistical model) demonstrate that a pressure of 140 bar, temperature of 102 °C and extraction time of 3.14 h are required to obtain optimum yield of β-carotene (1.028 × 10⁻²%) from the extraction process, however the maximum yield of the β-carotene (1.741 × 10⁻²%) was experimentally obtained at a pressure of 75 bar, temperature of 120 °C and extraction time of 1 h.     

Relationship between laser-induced fluorescence intensity and crude palm oil quality

Crude palm oil quality is an important consideration in the production of refined palm oil of consistent high quality. The quality of crude palm oil is determined by the analysis of oxidative and hydrolytic parameters such as peroxide value, anis dine value, free fatty acid content and moisture and impurities, all very time consuming and counter-productive for both crude palm oil mills and refineries to carry out. This study shows that laser-induced fluorescence (LIF) analysis can be used as an alternative to analysing all the common oxidative and hydrolytic parameters mentioned. LIF at 673 nm was indicative of the oxidative quality of crude palm oil. There was also positive correlation between fluorescence intensity and the carotene and the deterioration of bleach ability index of crude palm oil, and the Rancimat induction time of the final refined product.     

棕仁原油在温度梯度场中的结晶动力学研究

以棕仁原油为研究样品,借助于自行开发的试验装置,研究样品在不同温度梯度场中的结晶行为,得出晶体生长速率Rg以及结晶效率Y的变化规律并观察其晶体形态;同时借助于Avrami方程对试验数据进行模拟,得出确切的结晶动力学参数,如晶体形态n、结晶速率k、结晶半周期t1/2等,并采用双对数图对Avrami方程的拟合程度进行检验,以确定Avrami模型的适用性。     

Supercritical carbon dioxide extraction of the residual oil from palm kernel cake

Palm kernel cake contains residual oil that has never been retrieved and it is treated as wastes. In this study, supercritical carbon dioxide was used to separate the oil from the palm kernel matrix. The studied extraction parameters were at the set pressures 27.57, 34.47 and 41.36 MPa, temperatures 40-70 °C and carbon dioxide flow rate between 1 and 3 ml/min. The effect of the particle size on the oil yield was examined using different particle size that separated by sieving from ?106, ?150, ?180, ?250 and ?450 μm. The results showed that the highest oil removed was 9.26 g oil/100 g sample (p < 0.05) for the particle ?150 μm, and under extraction temperature of 70 °C, pressure 41.36 MPa, and carbon dioxide flow rate of 2 ml/min. The experimental results indicate that supercritical carbon dioxide extraction could be a viable technique to remove the remaining oil and to produce defatted palm kernel cake.     

Extraction and physicochemical properties of low free fatty acid crude palm oil

Response surface methodology was applied to optimize the pre-treatment of oil palm (Elaeis guineensis) fruit spikelets before oil extraction. The treatment applied was drying at different times and temperatures. The dried spikelets were then subjected to mechanical processes and crude oil was extracted. A central composite design was employed to study the responses, namely percentage of free fatty acids (FFA) and oil yield, and the optimum conditions for minimum FFA and maximum oil yield were identified from their respective contour plots. It was concluded that the pre-treatment should be carried out for 12.8 h at 66.8 °C. Under the optimum conditions, the corresponding response values for FFA and oil yield were 1% and 33.6%, respectively. Some of the physicochemical properties of the extracted oil were then determined. The low free fatty acid crude palm oil exhibited good physicochemical properties and could be useful for industrial applications.     

Partial purification and some properties of the lipase present in oil palm (Elaeis guineensis) mesocarp

The fatty layer obtained by centrifuging a homogenate of oil palm fruit mesocarp contains an active lipase. The lipase which was partially purified using a combination of ammonium sulphate fractionation, ion exchange and gel filtration chromatography, indicated an optimum activity at pH 4.5 and a temperature of 30°C. The enzyme exhibited good activity towards its natural substrate, palm oil as well as glycerol trioleate and glycerol tripalmitate. It also showed a linear reaction rate for the first 20 min of incubation. Sodium cyanide, resorcinol, cholesterol, lecithin and glycylglycine strongly inhibited its activity while phenol, L-cysteine and EDTA enhanced its activity. It is suggested that the lipase is associated with the membrane of the oil droplets.     

三文鱼鱼骨油粗提工艺优化及脂肪酸组成分析

鱼骨油是三文鱼加工的副产物。采用溶剂法提取三文鱼鱼骨油,通过优化溶剂种类、料液比、水浴时间、水浴温度和提取次数五个单因素,发现料液比、水浴时间和水浴温度三个因素对三文鱼鱼骨油粗得率影响较为显著(p 0.05)。之后通过响应面优化实验得出提取三文鱼鱼骨油的最佳工艺参数是:液料比15∶1 mL/g、水浴时间1.63 h、水浴温度60℃,此条件下三文鱼鱼骨中鱼油实际粗得率为22.62±0.22%。最后,经气相色谱法测定三文鱼鱼骨油的脂肪酸组成发现,鱼骨油中富含不饱和脂肪酸(Unsaturated fatty acid,UFA),相对含量高达70.77%,其中单不饱和脂肪酸(Monounsaturated fatty acid,SFA)主要由油酸(Oleic acid,C_(18):1_(n-9))和棕榈油酸(9-Hexadecenoic acid,C_(16):1_(n-9))组成,占脂肪酸相对含量的33.26%,多不饱和脂肪酸(polyunsaturated fatty acid,PUFA)相对含量为37.51%,主要为二十碳五烯酸(Eicosapntemacnioc acid,EPA)14.59%、α-亚麻酸(麻酸Linolenic acid,ALA)13.41%、二十二碳六烯酸(Docose Hexaenoie Acid,DHA)5.41%, n-3 PUFA占总脂肪酸相对含量的33.41%,饱和脂肪酸(Saturated fatty acid,SFA)成分是棕榈酸(palmitic acid,C_(16):0),相对含量仅为29.22%。综上,三文鱼鱼骨油不仅具有良好的油脂提取效率,在脂肪酸组成方面也具备良好的营养价值及经济效应。     

棕榈油和棕榈仁油的地位和现状

中国是一个油脂资源非常贫乏的国家 ,每年都要从国外进口大量的油脂以满足人民生活及工业需要。据统计 ,1997年中国进口的大豆油是 2 0 0万吨 ,棕榈油 16 2万吨 ,棕榈仁油 1 5万吨 ,其中棕榈油的消费量已位居第 4(见表 2 )。预计 ,至 2 0 0 5年 ,世界棕榈油的消费量将超过大豆油 (见表 1)。作为具有巨大市场潜力和价值的油脂资源 ,国外就棕榈油和棕榈仁油的生产、物理和化学性质及其应用等方面的研究已日趋深入[1] ,但在我国有关棕榈油和棕榈仁油的研究和介绍资料极少。为此 ,希望通过本文的介绍 ,能加深对棕榈油和棕榈仁油的了解 ,并能引起…     

小米麸皮膳食纤维提取工艺的研究

以非糯性小米麸皮为原料,研究了酶与化学结合法提取膳食纤维的工艺技术。结果表明,提取膳食纤维的最佳工艺条件为:在65℃条件下用4%的混合酶(α-淀粉酶∶糖化酶=1∶4)酶解100min,再用5%NaOH在100℃下处理70min,膳食纤维纯度为92%。     

坛紫菜水溶膳食纤维二次正交旋转组合法提取工艺的优化及其抗油脂氧化研究

以坛紫菜为原料,采用复合酶法提取水溶性膳食纤维,以猪油、菜油为材料考察其抗油脂氧化作用。在单因素实验基础上,采用二次正交旋转组合设计法对坛紫菜水溶性膳食纤维提取工艺进行优化,建立纤维素酶添加量(X1)、酶解pH(X2)、酶解温度(X3)和酶解时间(X4)等4个因素与水溶性膳食纤维提取率之间的回归模型。结果表明:纤维素酶法提取的最佳工艺参数为酶添加量1.1%、酶解pH5.8、酶解温度55℃和酶解时间1.5h,在此条件下坛紫菜水溶性膳食纤维提取率为9.80%±0.12%;膨胀力为1.97mL/g,持水力为276%,坛紫菜水溶性膳食纤维能明显减缓油脂POV值升高趋势,且具有一定的时间和浓度依赖性,显示坛紫菜可溶性膳食纤维具有一定的抗油脂氧化能力。      

不同提取方法对辣木籽原油和精炼油品质的影响

为探索辣木籽油的高效提取方法,以辣木籽为原料,分别采用索氏抽提法、乙醇水法和水酶法提取辣木籽原油,通过脱胶、脱酸工艺制备辣木籽精炼油,测定辣木籽原油和精炼油的理化指标、叶绿素和类胡萝卜素含量及脂肪酸组成,分析不同提取方法对辣木籽原油和精炼油品质的影响。结果表明：乙醇水法对辣木籽油的气味有一定影响,3种提取方法对辣木籽原油和精炼油的色泽和透明度影响不大;3种提取方法中,水酶法辣木籽原油的酸值,其原油和精炼油的碘值、水分及挥发物含量均最大,氧化诱导时间最长,叶绿素和类胡萝卜素含量最低;3种提取方法对辣木籽油的脂肪酸组成及相对含量无显著影响(p>0.05)。综上,3种提取方法中水酶法提取的辣木籽油的品质总体上较优。     

棕榈仁冷榨饼造粒浸出制油的工艺研究

为改善棕榈仁进料饼粕质量,提高棕榈仁油浸出效率,通过对压榨饼进行造粒后再浸出制油的工艺进行了探索性研究,系统地考察了物料水分、模板孔径对造粒过程的影响,比较分析了造粒料与未造粒料的浸出效果。试验结果表明:造粒过程中机械力可以有效的破碎压榨过程没有破碎的棕榈仁,提高物料的渗透性和浸出效果。对于含油18%的棕榈仁压榨饼造粒,其最佳造粒水分为9.5%～10.5%,造粒模板孔径4mm,浸出粕的残油在0.86%～0.93%之间,比压榨饼直接浸出可降低粕中残油0.7%～0.8%。